Document Detail

Dynamic graciloplasty for urinary incontinence: the potential for sequential closed-loop stimulation.
MedLine Citation:
PMID:  14519348     Owner:  NLM     Status:  MEDLINE    
Muscle tissue transplantation applied to regain or dynamically assist contractile functions is known as 'dynamic myoplasty'. Success rates of clinical applications are unpredictable, because of lack of endurance, ischemic lesions, abundant scar formation and inadequate performance of tasks due to lack of refined control. Electrical stimulation is used to control dynamic myoplasties and should be improved to reduce some of these drawbacks. Sequential segmental neuromuscular stimulation improves the endurance and closed-loop control offers refinement in rate of contraction of the muscle, while function-controlling stimulator algorithms present the possibility of performing more complex tasks. An acute feasibility study was performed in anaesthetised dogs combining these techniques. Electrically stimulated gracilis-based neo-sphincters were compared to native sphincters with regard to their ability to maintain continence. Measurements were made during fast bladder pressure changes, static high bladder pressure and slow filling of the bladder, mimicking among others posture changes, lifting heavy objects and diuresis. In general, neo-sphincter and native sphincter performance showed no significant difference during these measurements. However, during high bladder pressures reaching 40 cm H(2)O the neo-sphincters maintained positive pressure gradients, whereas most native sphincters relaxed. During slow filling of the bladder the neo-sphincters maintained a controlled positive pressure gradient for a prolonged time without any form of training. Furthermore, the accuracy of these maintained pressure gradients proved to be within the limits set up by the native sphincters. Refinements using more complicated self-learning function-controlling algorithms proved to be effective also and are briefly discussed. In conclusion, a combination of sequential stimulation, closed-loop control and function-controlling algorithms proved feasible in this dynamic graciloplasty-model. Neo-sphincters were created, which would probably provide an acceptable performance, when the stimulation system could be implanted and further tested. Sizing this technique down to implantable proportions seems to be justified and will enable exploration of the possible benefits.
Erik D H Zonnevijlle; Gustavo Perez-Abadia; Richard W Stremel; Claudio J Maldonado; Moshe Kon; John H Barker
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Medical engineering & physics     Volume:  25     ISSN:  1350-4533     ISO Abbreviation:  Med Eng Phys     Publication Date:  2003 Nov 
Date Detail:
Created Date:  2003-10-01     Completed Date:  2004-06-10     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9422753     Medline TA:  Med Eng Phys     Country:  England    
Other Details:
Languages:  eng     Pagination:  755-63     Citation Subset:  IM    
Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Louisville, Louisville, KY, USA.
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MeSH Terms
Electric Stimulation Therapy / instrumentation,  methods*
Equipment Design
Feasibility Studies
Muscle Contraction*
Muscle, Skeletal / innervation,  physiopathology*,  transplantation*
Online Systems
Therapy, Computer-Assisted / instrumentation,  methods*
Thigh / physiopathology
Treatment Outcome
Urinary Incontinence / physiopathology,  rehabilitation*,  surgery*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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